No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Base Deficit as a Guide to Volume Resuscitation
Abstract
The base deficit (BD), is a potentially useful indicator of volume deficit in trauma patients. To evaluate BD as an index for fluid resuscitation, the records of 209 trauma patients with serial arterial blood gases (ABG's) were reviewed. The patients were grouped according to initial BD: mild, 2 to -5; moderate, -6 to -14; and severe, less than -15. The volume of resuscitative fluid administered, change in BD, mean arterial pressure (MAP), and presence of ongoing hemorrhage were analyzed for differences between the BD groups. The MAP decreased significantly and the volume of fluid required for resuscitation increased with increasing severity of BD group. A BD that increased (became more negative) with resuscitation was associated with ongoing hemorrhage in 65%. The data suggest that the BD is a useful guide to volume replacement in the resuscitation of trauma patients.
... Clinical studies have shown a direct correlation between the magnitude of the increase in base deficit at presentation and the extent of blood loss. 23 In addition, correction of the base deficit within hours after volume replacement is associated with a favorable outcome, 23 whereas persistent elevations in base deficit are often a harbinger of multiorgan failure. Similarly, lactate concentration is a prognostic factor in circulatory shock. ...
... Clinical studies have shown a direct correlation between the magnitude of the increase in base deficit at presentation and the extent of blood loss. 23 In addition, correction of the base deficit within hours after volume replacement is associated with a favorable outcome, 23 whereas persistent elevations in base deficit are often a harbinger of multiorgan failure. Similarly, lactate concentration is a prognostic factor in circulatory shock. ...
... Further fluid resuscitation should be aimed at restoring adequate blood flow (SBP >90 mm Hg and mean arterial pressure [MAP] >65 mm Hg) to prevent tissue hypoperfusion and correct tissue dysoxia as evidenced by monitoring arterial base deficit, arterial lactate concentration, and SvO 2 . [23][24][25][26] Central venous pressure (CVP) and stroke volume variation (SVV) can be used to help clinicians determine the patient's intravascular volume and the need for further IV fluid administration. Conventionally CVP is probably the most used parameter for judging whether fluids should be administered. ...
... [5] Similar to lactate, decreased BD was also associated with unfavorable outcomes in critical patients. [6][7][8] Studies have demonstrated that clearance of both lactate and BD are associated with volume of resuscitation required; the need for transfusion of blood products and mortality in trauma patients [9,10] and initial blood lactate and BD are both considered as useful biomarkers in trauma patients. [11,12] Although BD and lactate are widely used in predicting outcome in trauma patients, studies investigating the use of their combination are more recent. ...
... Serial measurements of lactate and BD revealed their effectiveness for mortality in the management of patients in shock. [9,10,37] Vandromme et al. [32] showed that blood lactate value is a better indicator than SBP in identifying patients who need transfusion. Low BD was also associated with blood transfusion necessity. ...
Background:
Lactate and base deficit (BD) values are parameters evaluated as indicators of tissue perfusion and have been used as markers of severity of injury and mortality.
Objectives:
The aim of the study was to determine the relationship between combined score (CS) and blood transfusion need within 24 h and comparison of the variables between transfusion and non-transfusion group, correlation lactate with BD and with physiological, laboratory parameters, and determining the major risk factors of patients for the need for blood transfusion.
Methods:
The study included a total of 359 patients (245 males, median age: 40, min-max: 18-95) with blunt multi-trauma. De-mographics data, laboratory parameters (hemoglobin [Hb], hematocrit [Htc], lactate, BD, pH), physiologic parameters (systolic blood pressure [SBP], diastolic blood pressure [DBP], heart rate [HR], respiratory rate [RR]), shock index (SI), and revised trauma score (RTS) were recorded. Logistic regression method was used to create the CS formula using lactate and BD values. According to this formula, the probability value of 0.092447509 was calculated for the need for blood transfusion within 24 h. If CS was higher than the probability value, the need for blood transfusion within 24 h was considered. Furthermore, univariate analysis was used to determine major risk for blood transfusion need in 24 h, and the receiver operating characteristic curves were performed to compare CS, lactate, BD, SI and RTS.
Results:
The comparison between transfusion and non-transfusion group there was significance between SBP, DBP, HR, RR, SpO2, Glasgow coma scale, Hb, Htc, lactate, BD, pH, SI and RTS (for each p<0.05). Lactate value has a positive correlation with SI, HR and has a negative correlation with BD, RTS, SBP, and DBP. BD values has a positive correlation with RTS, SBP, DBP, Hb, and Htc and has a negative correlation with SI, HR, and RR. The main risks for blood transfusion need were SI, lactate, BD, SBP, and SpO2%. CS was 0.09 in 100 (27.85%) patients and 41 with high CS had blood transfusion within 24 h (p<0.001; OR21.803, sensitivity 83.7%, specificity 81%,positive predictive value 41%, and negative predictive value 96.9%). A ROC curve showed that CS (AUC: 86.) was more significant than SI and RTS for the need for blood transfusion.
Conclusion:
CS is effective for predicting blood necessity in 24 h for blunt multi-trauma patients.
... A negative BE is sometimes referred to as a "base deficit". BE plays a vital role in evaluation of symptoms related to the management of acid-base ratio, and it has a significant role in early diagnosis/assessment and treatment of the patients [1][2][3][4][5] . ...
... Several studies have reported the association between BE and the need for blood transfusion in trauma patients in general. However, this has not been thoroughly studied in head injury patients [3,[21][22][23] . ...
... There is an abundance of literature on the value of standard base excess as one of the most important tools in determining the severity of illness in the acute care setting. [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64] One study, involving more than 16,000 patients, compared standard base excess with the Advanced Trauma Life Support (ATLS) hypovolemic-shock classification, which combines heart rate, systolic blood pressure, and score on the Glasgow Coma Scale. 50 Standard base excess was found to be superior for detecting hypovolemic shock and stratifying patients in hemorrhagic shock with respect to the need for early transfusion of blood products. ...
... 6 Furthermore, in such patients, a standard base excess that is negative or becoming increasingly negative is considered to be predictive of transfusion requirements, 53,54 as well as of numerous shock-related complications, including a prolonged stay in the intensive care unit, renal failure, the acute respiratory distress syndrome, multiorgan failure, and acute lung injury. 27,[54][55][56][57][58] In the acute setting, standard base excess may also be correlated with the risk of potentially fatal coagulation disturbances in patients with trauma. 58 Measurement of standard base excess in patients with multiple sources of trauma has become common practice in emergency rooms, since many trauma specialists see it as predictive and crucial for guiding resuscitation efforts. ...
This review discusses the value of standard base excess and includes several case vignettes that show the benefit of the base-excess approach in clinical practice.
... It can be indicative of metabolic acidosis or compensatory respiratory alkalosis. The use of base deficit as a guide to volume resuscitation in trauma patients, was first established in 1988 by [10]. Since then, the base deficit has been correlated to many variables in the trauma population, such as mechanism of injury, the presence of intra-abdominal injury, transfusion requirements, mortality, the risk of complications, and the number of days spent in the intensive care unit (see, [35] and [9]). ...
The kernel-based estimator of Cochran Mantel-Haenszel odds ratio based on stratified simple and ranked set sampling is proposed. The expectation and variance of the estimator are analytically obtained. Using a simulation study, the estimator based on stratified ranked set sampling is more efficient than its counterpart based on stratified simple random sampling. Finally, the estimator's performance is investigated by using base deficit data.
... There was a moderate, positive, linear relationship between serum lactate and TBSA, and moderate, negative linear relationship between serum BD and TBSA. This was indicative of increasing hypoperfusion and tissue ischaemia due to fluid loss associated with rising %TBSA [15]. ...
Objective: To correlate initial serum lactic acid and base deficit (BD) levels with early mortality in major thermal burns. Methods: This was a prospective descriptive study conducted over 6 months at Kenyatta National Hospital (KNH), Nairobi, Kenya. Ninety consecutive patients with major thermal burns exceeding 20% of total body surface area (TBSA), who met other inclusion criteria participated. Biographic and clinical data were collected using a structured questionnaire. Blood samples were drawn at admission for arterial blood gas analysis (ABGAs) to obtain serum lactic acid and BD levels. Patients were followed up for 7 days at KNH Burns Unit. Results: Studied patients had burns from 21% to 100% TBSA. Majority, 54(60%), had burns between 21% and 50% TBSA. 55(61.1%) patients died within 7 days after admission. 38(69.1%) of these deaths occured within the initial 48 h. Both mean serum lactic acid (P
... Tokarik et al suggested that GDFT by the LiDCO system measures intravascular fluid volume more accurately in comparison to assessing indirectly by urine output. [30] The normal range of base deficit is −2 to +2 mEq/L. Base deficit is a potentially useful indicator of volume deficit and is an important factor in the diagnosis of patients with underperfused tissues. ...
Background:
Goal-directed fluid therapy (GDFT) is a new concept to describe the cardiac output (CO) and stroke volume variation to guide intravenous fluid administration during surgery. LiDCOrapid (LiDCO, Cardiac Sensor System, UK Company Regd 2736561, VAT Regd 672475708) is a minimally invasive monitor that estimates the responsiveness of CO versus fluid infusion. We intend to find whether GDFT using the LiDCOrapid system can decrease the volume of intraoperative fluid therapy and facilitate recovery in patients undergoing posterior fusion spine surgeries in comparison to regular fluid therapy.
Methods:
This study is a randomised clinical trial, and the design was parallel. Inclusion criteria for participants in this study were patients with comorbidities such as diabetes mellitus, hypertension, and ischemic heart disease undergoing spine surgery; exclusion criteria were patients with irregular heart rhythm or severe valvular heart disease. Forty patients with a previous history of medical comorbidities undergoing spine surgery were randomly and evenly assigned to receive either LiDCOrapid guided fluid therapy or regular fluid therapy. The volume of infused fluid was the primary outcome. The amount of bleeding, number of patients who needed packed red blood cell transfusion, base deficit, urine output, days of hospital length of stay and intensive care unit (ICU) admission, and time needed to start eating solids were monitored as secondary outcomes.
Results:
The volume of infused crystalloid and urinary output in the LiDCO group was significantly lower than that of the control group (p = .001). Base deficit at the end of surgery was significantly better in the LiDCO group (p < .001). The duration of hospital length of stay in the LiDCO group was significantly shorter (p = .027), but the duration of ICU admission was not significantly different between the two groups.
Conclusion:
Goal-directed fluid therapy using the LiDCOrapid system reduced the volume of intraoperative fluid therapy.
... Several studies have shown that BE is one of the most important tools for determining the severity of illness in acute care settings (9,10,13,14). Miñana et al. revealed that admission pH, arterial PaO 2 , and PaCO 2 had no association with all-cause mortality in patients with HF (10). However, Park et al. found that the most popular acid-base imbalance was respiratory alkalosis in patients with high-risk AHF, and pH provided additional prognostic value for patients with high-risk AHF and may be helpful for risk stratification and patient care. ...
Background
Base excess (BE) represents an increase or decrease of alkali reserves in plasma to diagnose acid-base disorders, independent of respiratory factors. Current findings about the prognostic value of BE on mortality of patients with acute myocardial infarction (AMI) are still unclear. The purpose of this study was to explore the prognostic significance of BE for short-term all-cause mortality in patients with AMI.
Methods
A total of 2,465 patients diagnosed with AMI in the intensive care unit from the Medical Information Mart for Intensive Care III (MIMIC-III) database were included in our study, and we explored the association of BE with 28-day and 90-day all-cause mortality using Cox regression analysis. We also used restricted cubic splines (RCS) to evaluate the relationship between BE and hazard ratio (HR). The primary outcomes were 28-day and 90-day all-cause mortality.
Results
When stratified according to quantiles, low BE levels at admission were strongly associated with higher 28-day and 90-day all-cause mortality. Multivariable Cox proportional hazard models revealed that low BE was an independent risk factor of 28-day all-cause mortality [HR 4.158, 95% CI 3.203–5.398 (low vs. normal BE) and HR 1.354, 95% CI 0.896–2.049 (high vs. normal BE)] and 90-day all-cause mortality [HR 4.078, 95% CI 3.160–5.263 (low vs. normal BE) and HR 1.369, 95% CI 0.917–2.045 (high vs. normal BE)], even after adjustment for significant prognostic covariates. The results were also consistent in subgroup analysis. RCS revealed an “L-type” relationship between BE and 28-day and 90-day all-cause mortality, as well as adjusting for confounding variables. Meanwhile, Kaplan–Meier survival curves were stratified by combining BE with carbon dioxide partial pressure (PaCO 2 ), and patients had the highest mortality in the group which had low BE (< 3.5 mEq/L) and high PaCO 2 (> 45 mmHg) compared with other groups.
Conclusion
Our study revealed that low BE was significantly associated with 28-day and 90-day mortality in patients with AMI and indicated the value of stratifying the mortality risk of patients with AMI by BE.
... Her VBG analysis revealed metabolic acidosis with a base excess of -10.3 mmol/L. As we know, BE is a valuable point to determine whether volume depletion is present and is a helpful guide to volume resuscitation [12]. Therefore, we assumed that she needed more volume resuscitation than a vasoconstrictor medication, and despite the acceptable response, the dose of norepinephrine was reduced. ...
Nitroglycerin, a vasodilator, is commonly administered to treat ischemic heart disease. Adverse effects after toxicity are light-headedness, nausea, blurry vision, and syncope due to low systolic blood pressure as well as methemoglobinemia. A 19-year-old female was admitted to our toxicology department after suicidal ingestion of 320 mg extended-release nitroglycerin about 45 minutes before the admission. She was conscious, and her initial blood pressure was 98/65 mm Hg, which was decreased to 77 mmHg within 1.5 hours despite administration of 1 liter of normal saline. Due to severe hypotension, norepinephrine infusion was started for systolic blood pressure maintenance above 80mm Hg; however, she started complaining of palpitation and chest pain. So, the dose of norepinephrine was reduced, and glucose, insulin, and potassium protocol were started. After 3 hours of therapy, her hemodynamic condition stabilized with systolic blood pressure above 90mm Hg; hence norepinephrine was discontinued. She was discharged on the 3rd day after the psychiatric consultation, with regular clinical and paraclinical examinations.
... However, these parameters have a low sensitivity in young patients and should not be used as an isolated reference 28 . Up to 85% of the severely injured trauma patients with normal hemodynamic parameters could have occult hypoperfusion with persistently increased BE or lactate levels [29][30][31][32][33][34][35] . Therefore, the implementation of the tissue perfusion (BE and lactate levels) with the hemodynamic parameters contribute to a better physiological status assessment of the patient and adequate resuscitation guidance. ...
When trauma patients are admitted into the intensive care unit after undergoing damage control surgery, they generally present some degree of bleeding, hypoperfusion, and injuries that require definitive repair. Trauma patients admitted into the intensive care unit after undergoing damage control surgery can present injuries that require a definite repair, which can cause bleeding and hypoperfusion. The intensive care team must evaluate the severity and systemic repercussions in the patient. This will allow them to establish the need for resuscitation, anticipate potential complications, and adjust the treatment to minimize trauma-associated morbidity and mortality. This article aims to describe the alterations present in patients with severe trauma who undergo damage control surgery and considerations in their therapeutic approach. The intensivist must detect the different physiological alterations presented in trauma patients undergoing damage control surgery, mainly caused by massive hemorrhage. Monitor and support strategies are defined by the evaluation of bleeding and shock severity and resuscitation phase in ICU admission. The correction of hypothermia, acidosis, and coagulopathy is fundamental in the management of severe trauma patients.
... 29 The endpoints of resuscitation are measured by the base deficit and normalization of serum lactate. 30 Their elevated levels have a direct correlation with mortality. However, maintaining the systolic blood pressure of 80e90 mmHg, urinary output, and palpable peripheral pulse are not consistent signs of successful resuscitation. ...
Pelvic injuries are notorious for causing rapid exsanguination, and also due to concomitant injuries and complications, they have a relatively higher mortality rate. Management of pelvic fractures in hemodynamically unstable patients is a challenging task and has been variably approached. Over the years, various concepts have evolved, and different guidelines and protocols were established in regional trauma care centers based mainly on their previous experience, outcomes, and availability of resources. More recently, damage control resuscitation, pelvic angioembolization, and acute definitive internal fixation are being employed in the management of these unstable injuries, without clear consensus or guidelines. In this background, we have performed a computerized search using the Cochrane Database of Systematic Reviews, Scopus, Embase, Web of Science, and PubMed databases on studies published over the past 30 years. This comprehensive review aims to consolidate available literature on the current epidemiology, diagnostics, resuscitation, and management options of pelvic fractures in polytraumatized patients with hemodynamic instability with particular focus on damage control resuscitation, pelvic angioembolization, and acute definitive internal fixation.
... It has been shown that none of these parameters is adequately sensitive or specific to detect early hemorrhage [43]. Serum markers like lactate or base deficit determine tissue hypoperfusion and global tissue acidosis, respectively, and are the most commonly used serum markers for hemorrhagic shock [44][45][46][47][48]. These two parameters likewise correlated with I-FABP in the present study. ...
Background
Hemorrhagic shock can lead to intestinal damage with subsequent hyperinflammation and multiple organ dysfunction syndrome (MODS). The intestinal fatty acid-binding protein (I-FABP) is solely expressed in the intestine and is released extracellulary after tissue damage. This study evaluates the validity of I-FABP as an early biomarker to detect hemorrhagic shock and abdominal injury.
Patients and methods
Severely injured patients with an Injury Severity Score (ISS) ≥ 16 points and an age ≥ 18 years, admitted from January 2010 to December 2016, were included. Overall, 26 patients retrospectively presented with hemorrhagic shock to the emergency room (ER): 8 patients without abdominal injury (“HS noAbd”) and 18 patients with abdominal injury (“HS Abd”). Furthermore, 16 severely injured patients without hemorrhagic shock and without abdominal injury (“noHS noAbd”) were retrospectively selected as controls. Plasma I-FABP levels were measured at admission to the ER and up to 3 days posttraumatic (d1-d3).
Results
Median I-FABP levels were significantly higher in the “HS Abd” group compared with the “HS noAbd” group (28,637.0 pg/ml [IQR = 6372.4–55,550.0] vs. 7292.3 pg/ml [IQR = 1282.5–11,159.5], p < 0.05). Furthermore, I-FABP levels of both hemorrhagic shock groups were significantly higher compared with the “noHS noAbd” group (844.4 pg/ml [IQR = 530.0–1432.9], p < 0.05). The time course of I-FABP levels showed a peak on the day of admission with a subsequent decline in the post-traumatic course. Furthermore, significant correlations between I-FABP levels and clinical parameters of hemorrhagic shock, such as hemoglobin, lactate value, systolic blood pressure (SBP), and shock index, were found.
The optimal cut-off level of I-FABP for detection of hemorrhagic shock was 1761.9 pg/ml with a sensitivity of 85% and a specificity of 81%.
Conclusion
This study confirmed our previous observation that I-FABP might be used as a suitable early biomarker for the detection of abdominal injuries in general. In addition, I-FABP may also be a useful and a promising parameter in the diagnosis of hemorrhagic shock, because of reflecting low intestinal perfusion.
... In the current study, there was no difference between both groups regarding mortality, outcome or inhospital complication rates. This is interesting, as the BE parameter is used as an indicator of trauma severity, mortality, shock severity and volume requirement [34][35][36][37][38]. Among others, through the study of Abt et al, the relation between the BE value as a predictor of mortality in the context of trauma patients was demonstrated [34]. ...
Background and purpose
In the diagnosis and treatment of trauma patients, numerous individual and trauma-related factors must be considered, all of which may influence the outcome. Although alcohol exposure is a major risk factor for an accident, its influence on the outcome is unclear. This matched-pair analysis investigates the hypothesis that alcohol has no negative impact on the outcome of trauma patients.
Materials and methods
In a retrospective matched-pair analysis of the multi-centre database of the TraumaRegister DGU® patients with a maximum Abbreviated Injury Scale (MAIS) of 3 or greater from the years 2015 and 2016 with an alcohol level ≥ 0.5‰ were compared to patients with a measured alcohol level of 0.0‰. The patients were matched according to age, gender, AIS body regions (head, thorax, abdomen, pelvis/extremities) and survival presumption (Revised Injury Severity Classification Score (RISC) II the TraumaRegister ervals).
Results
After matching, a total of 834 patients were enrolled, with 417 patients in group with positive blood alcohol levels (BAL +) with a median alcohol level of 1.82‰ and 417 patients in the negative-alcohol group (BAL −). As a mechanism of injury, the BAL + group showed more often penetrating injuries, pedestrian accidents and low energy falls compared to car and motorcycle accidents in the BAL − group. BAL + patients were significantly less sedated (BAL −: 66.7% vs. BAL + : 56.2%, p = 0.002), less frequently transported by rescue helicopter, were more frequently hypotensive (BAL −: 42 patients (10.3%) vs. BAL + : 61 patients (15.2%), p = 0.045, Table 2) and exhibited lower base excess levels associated with an acidotic metabolic status compared to sober patients (acidosis: BAL −: 24 patients (6.1%) vs. BAL + : 61 patients (17.2%), p < 0.001). There was no difference regarding in-hospital complications, length of stay or mortality rate.
Conclusions and implications
Our data demonstrate that alcohol exposure in trauma patients has no impact on complication or mortality rates. On the other hand, there are initially clear differences in the mechanism of injury, sedation, mode of transport and the acid–base balance.
... Other measures, such as shock index (HR/SBP), base deficit, or serum lactate level may prove useful in predicting severity of shock and poor outcomes or intervention. [10][11][12][13] Further analysis may provide insight into what factors should be emphasized. ...
Background:
The Advanced Trauma Life Support (ATLS) shock classification has been accepted as the conceptual framework for clinicians caring for trauma patients. We sought to validate its ability to predict mortality, blood transfusion, and urgent intervention.
Materials and methods:
We performed a retrospective review of trauma patients using the 2014 National Trauma Data Bank. Using initial vital signs data, patients were categorized into shock class based on the ATLS program. Rates for urgent blood transfusion, urgent operative intervention, and mortality were compared between classes.
Results:
630,635 subjects were included for analysis. Classes 1, 2, 3, and 4 included 312,404, 17,133, 31, and 43 patients, respectively. 300,754 patients did not meet criteria for any ATLS shock class. Of the patients in class 1 shock, 2653 died (0.9%), 3123 (1.0%) were transfused blood products, and 7115 (2.3%) underwent an urgent procedure. In class 2, 219 (1.3%) died, 387 (2.3%) were transfused, and 1575 (9.2%) underwent intervention. In class 3, 7 (22.6%) died, 10 (32.3%) were transfused, and 13 (41.9%) underwent intervention. In class 4, 15 (34.9%) died, 19 (44.2%) were transfused, and 23 (53.5%) underwent intervention. For uncategorized patients, 21,356 (7.1%) died, 15,168 (5.0%) were transfused, and 23,844 (7.9%) underwent intervention.
Conclusions:
Almost half of trauma patients do not meet criteria for any ATLS shock class. Uncategorized patients had a higher mortality (7.1%) than patients in classes 1 and 2 (0.9% and 1.3%, respectively). Classes 3 and 4 only accounted for 0.005% and 0.007%, respectively, of patients. The ATLS classification system does not help identify many patients in severe shock.
... Although multiple preclinical scoring systems have been described, the availability of systems for the early clinical stages have been sparse. Most of these have focused on the prediction of massive transfusion (101), or used parameters of hemorrhagic shock to describe the risk of complications (102). In contrast, Kutcher et al. recently suggested looking at coagulopathy in a more detailed fashion, as coagulopathic patients present with mixed risk factors, and coagulopathy has deleterious effects independent of injury severity, shock, and the vicious triad (103). ...
Objectives:
Sustained changes in resuscitation and transfusion management have been observed since the turn of the millennium, along with an ongoing discussion of surgical management strategies. The aims of this study are threefold: a) to evaluate the objective changes in resuscitation and mass transfusion protocols undertaken in major level I trauma centers; b) to summarize the improvements in diagnostic options for early risk profiling in multiply injured patients and c) to assess the improvements in surgical treatment for acute major fractures in the multiply injured patient.
Methods:
I. A systematic review of the literature (comprehensive search of the MEDLINE, Embase, PubMed, and Cochrane Central Register of Controlled Trials databases) and a concomitant data base (from a single Level I center) analysis were performed. Two authors independently extracted data using a pre-designed form. A pooled analysis was performed to determine the changes in the management of polytraumatized patients after the change of the millennium. II. A data base from a level I trauma center was utilized to test any effects of treatment changes on outcome.
Inclusion criteria:
adult patients, ISS > 16, admission < less than 24 h post trauma. Exclusion: Oncological diseases, genetic disorders that affect the musculoskeletal system. Parameters evaluated were mortality, ICU stay, ICU complications (Sepsis, Pneumonia, Multiple organ failure).
Results:
I. From the electronic databases, 5141 articles were deemed to be relevant. 169 articles met the inclusion criteria and a manual review of reference lists of key articles identified an additional 22 articles. II. Out of 3668 patients, 2694 (73.4%) were male, the mean ISS was 28.2 (SD 15.1), mean NISS was 37.2 points (SD 17.4 points) and the average length of stay was 17.0 days (SD 18.7 days) with a mean length of ICU stay of 8.2 days (SD 10.5 days), and a mean ventilation time of 5.1 days (SD 8.1 days). Both surgical management and nonsurgical strategies have changed over time. Damage control resuscitation, dynamic analyses of coagulopathy and lactate clearance proved to sharpen the view of the worsening trauma patient and facilitated the prevention of further complications. The subsequent surgical care has become safer and more balanced, avoiding overzealous initial surgeries, while performing early fixation, when patients are physiologically stable or rapidly improving. Severe chest trauma and soft tissue injuries require further evaluation.
Conclusions:
Multiple changes in management (resuscitation, transfusion protocols and balanced surgical care) have taken place. Moreover, improvement in mortality rates and complications associated with several factors were also observed. These findings support the view that the management of polytrauma patients has been substantially improved over the past 3 decades.
... Although traditionally arterial BD has been widely accepted as a reliable early indicator of the magnitude of volume deficit which predicts transfusion requirements and mortality in trauma patients [3,28], its value can be confounded by a number of factors such as alcohol intoxication, hypoalbuminemia, hypothermia and hypocapnea [29][30][31][32]. ...
Introduction
Arterial blood gas (ABG) sampling is routinely performed in major trauma patients to assess the severity of hemorrhagic shock. Compared to venous blood gas (VBG), ABG is an additional procedure with risks of hematoma and pain. We aim to determine if pH, base deficit (BD), and lactate from VBG and ABG in trauma patients are clinically equivalent. If proven, the need for ABG and its associated risks can be eliminated.
Methods
This prospective observational study was conducted in the Emergency Department of National University Hospital, Singapore, between February and October 2016. We correlated paired ABG and VBG results in adult trauma patients. VBG and ABG were obtained within 10 min and processed within 5 min using a point-of-care blood gas analyzer. Bland–Altman plot analysis was used to evaluate the agreement between peripheral VBG and ABG in terms of pH, base deficit and lactate.
Results
There were 102 patients included, with a median age of 34 (interquartile range 28–46) years and male predominance (90.2%). Majority of patients sustained blunt trauma (96.1%), and had injuries of Tier 1 and Tier 2 severity (60/102, 58.8%). Bland–Altman plot analyses demonstrated that only 72.6% of venous pH and 76.5% of venous BD lie within the pre-defined clinically acceptable limits of agreement, whereas 96.0% of venous lactate was within these limits.
Conclusion
Venous and arterial pH and BD are not within clinically acceptable limits of agreement, and ABG should be obtained for accurate acid–base status. However, venous lactate may be an acceptable substitute for arterial lactate.
... Base deficit is a simple measure of the metabolic acid-base activity defined by the amount of strong base required to return the pH of 1 l of whole blood to 7.4 assuming a PCO2 of 40 mmHg and a temperature of 378C [21]. There are many reports in the trauma literature on the clinically significant correlation between shock status and the level of lactate and base deficit in blood in which the degree of base deficit is correlated with blood transfusion requirements, multiorgan dysfunction, and mortality in trauma patients [22][23][24][25][26]. Our results are consistent with a previous study utilizing metabolic acid-base derangement as a prognostic indicator of mortality in pediatric patients during the first 24 h after CPB surgery [27]. ...
: We evaluated clinical and laboratory biomarkers of disseminated intravascular coagulation (DIC) following cardiac surgery in the cardiothoracic surgical ICU (CTICU) to predict mortality. We retrospectively analyzed CTICU patients with suspected DIC identified from the hospital laboratory database, and calculated International Society on Thrombosis and Haemostasis (ISTH) and the Japanese Association for Acute Medicine (JAAM) DIC scores to predict DIC-related mortality. The predictive accuracy of the JAAM and ISTH DIC scoring system were then assessed by logistic regression analysis and receiver operative characteristics analysis, and compared to other potential predictors of mortality (e.g., Acute Physiology and Chronic Health Evaluation II, systemic inflammatory response syndrome criteria, laboratory variables). Our study showed a 30-day mortality rate of 71% in CTICU patients with DIC. The JAAM DIC score offered the best predictive accuracy [area under the curve (AUC): 0.723, 95% % confidence interval (CI): 0.638-0.947, P = 0.021], when compared with ISTH DIC score (AUC: 0.707, 95% CI: 0.491-0.923, P = 0.066) and Acute Physiology and Chronic Health Evaluation II (AUC: 0.687, 95% CI: 0.483-0.891, P = 0.110). A JAAM DIC score at least 6 was reported in 89% of the nonsurvivors and 46% of survivors (P = 0.010), and predicted mortality [odds ratio: 9.33 (1.50-58.20)] with a 73% sensitivity and a 78% specificity. Our results also show a strong relationship between acid-base derangement and mortality. This initial evaluation of DIC-related mortality in the CTICU found the standardized JAAM DIC scoring system in combination with acid-base laboratory values were most useful to predict mortality in postcardiac surgery patients with DIC. Additional prospective studies are needed to further validate our findings.
... They have also been claimed to accurately reflect hemodynamic and tissue perfusion changes. 18,19 Abramson 20 et al have demonstrated 100% survival in patients who cleared lactate within 24h. Survival fell to 15% in patients who had persistent lactic acidosis. ...
In the last two decades resuscitation strategies have gone through revolutionary changes. Ideas once held
sacred have been questioned and the very foundations on which these strategies were based shaken.
Resuscitation strategies basically revolve around three questions:
1. How much?
2. How fast?
3. When to stop?
Evolutions of shocked patient management concepts show three distinct phases.
• Phase 1 – Clinical parameter based.
• Phase 2 – Oxygen variables based.
• Phase 3 – Cellular perfusion based.
Accepted criteria for endpoints of resuscitation too have undergone similar changes in paradigm and can
be grouped under similar phases.
Key Words: Shock, Clinical parameter, cellular perfusion, resuscitation.
... SaO2 values of <80% could prevent the oxygen from penetrating the tissue, particularly for organs requiring high oxygen consumption, such as the brain, liver, and kidney. Hypoxemia is the condition in which there is a lack of SaO2 and PO2 and is classified as mild, medium, or severe [19]. ...
Environmental suffocation is a form of asphyxia. In such cases, an autopsy alone is not sufficient to determine the cause of death, and forensic pathologists need environmental data from the scene and the symptoms of hypoxia from the victim. Considering that the symptoms of hypoxia vary widely, the analysis of gases in the blood is used to assess the level of oxygenation in humans. No research has yet equated a specific level of oxygen in the air with environmental suffocation. This study aimed to determine the correlation among the decreased level of oxygen in the environment, the values of blood gases, and the emergence of the symptoms of hypoxia. Pig animal model (Sus scrofa) was used. This study induced a state of environmental suffocation in the pigs, which were placed in a chamber with oxygen levels decreasing from 21% to 11% and then to 7%. At each oxygen level, the symptoms of hypoxia and the values of arterial blood gases were assessed. It is concluded that the decreased oxygen levels in the chamber resulted in hypoxia symptoms such as changes in the respiratory rate, heart rate, and blood gases, such as the pH, PO2, PCO2, HCO3, BE, and O2 saturation values. These changes had different percentages that reflect each range of the decreased oxygen levels in the chamber.
... The higher haemoglobin values in the ethyl pyruvate group compared to the control group also explain the difference with regard to the blood pressure between those two groups at the end of the resuscitation period. Considering that the base deficit is a known indicator for trauma severity, outcome and resuscitation success [45,[49][50][51]12], the better recovery in the ethyl pyruvate group underlines the beneficial potential of ethyl pyruvate as resuscitation fluid. Regarding the total protein content and tHb levels, the TxT+H/R_EP group exhibited higher protein values compared to the TxT+H/R_RL group and slightly lower values compared to the sham group (TxT+H/R_RL: 3.32 ± 0.28 g/dL vs. sham: 4.27 ± 0.17 g/ dL and TxT+H/R_EP: 4.10 ± 0.27 g/dL, respectively, p<0.05, ...
Background:
The treatment of patients with multiple trauma including blunt chest/thoracic trauma (TxT) and hemorrhagic shock (H) is still challenging. Numerous studies show detrimental consequences of TxT and HS resulting in strong inflammatory changes, organ injury and mortality. Additionally, the reperfusion (R) phase plays a key role in triggering inflammation and worsening outcome. Ethyl pyruvate (EP), a stable lipophilic ester, has anti-inflammatory properties. Here, the influence of EP on the inflammatory reaction and liver injury in a double hit model of TxT and H/R in rats was explored.
Methods:
Female Lewis rats were subjected to TxT followed by hemorrhage/H (60 min, 35±3 mm Hg) and resuscitation/R (TxT+H/R). Reperfusion was performed by either Ringer`s lactated solution (RL) alone or RL supplemented with EP (50 mg/kg). Sham animals underwent all surgical procedures without TxT+H/R. After 2h, blood and liver tissue were collected for analyses, and survival was assessed after 24h.
Results:
Resuscitation with EP significantly improved haemoglobin levels and base excess recovery compared with controls after TxT+H/R, respectively (p<0.05). TxT+H/R-induced significant increase in alanine aminotransferase levels and liver injury were attenuated by EP compared with controls (p<0.05). Local inflammation as shown by increased gene expression of IL-6 and ICAM-1, enhanced ICAM-1 and HMGB1 protein expression and infiltration of the liver with neutrophils were also significantly attenuated by EP compared with controls after TxT+H/R (p<0.05). EP significantly reduced TxT+H/R-induced p65 activation in liver tissue. Survival rates improved by EP from 50% to 70% after TxT+H/R.
Conclusions:
These data support the concept that the pronounced local pro-inflammatory response in the liver after blunt chest trauma and hemorrhagic shock is associated with NF-κB. In particular, the beneficial anti-inflammatory effects of ethyl pyruvate seem to be regulated by the HMGB1/NF-κB axis in the liver, thereby, restraining inflammatory responses and liver injury after double hit trauma in the rat.
... Obrnuto, što je BE pozitivniji (>+2 mEq/L), u organizmu postoji višak baza odnosno razvila se alkaloza. Praktično, negativan BE je aktuelni bazni deficit bikarbonata; neke laboratorije ga određuju kao poseban acido-bazni parametar [11,13]. ...
... Studies of trauma subjects have found the base deficit from ABGs correlates with outcomes 25,26 and is useful to guide resuscitation. 27,28 Moreover, hemoglobin levels, an important clinical data point in the trauma population, can be evaluated quickly at bedside using ABG analyzers. Therefore, the differential use of ABGs in this subgroup may have been influenced by the trauma teams' involvement. ...
Background:
Mechanically ventilated patients increasingly spend hours in emergency department beds before ICU admission. This study evaluated the performance of blood gases in mechanically ventilated subjects in the emergency department and subsequent changes to mechanical ventilation settings.
Methods:
This was a multi-center, prospective, observational study of subjects ventilated in the emergency department, conducted at 3 academic emergency departments from July 2011 to March 2013. We measured the rate of arterial blood gas (ABG) and venous blood gas (VBG) analysis, and we assessed the associations between the conditions of hypoxemia, hyperoxia, hypercapnia, or acidemia and changes to mechanical ventilator settings.
Results:
Of 292 ventilated subjects, 17.1% did not have a blood gas sent in the emergency department. Ventilator changes were made significantly more frequently for subjects who had an ABG as the initial blood gas sent in the emergency department (odds ratio 2.70, 95% CI 1.46-4.99, P = .002). However, findings of hypoxemia, hyperoxia, hypercapnia, or acidemia were not correlated with ventilator adjustments.
Conclusions:
In this prospective observational study of subjects mechanically ventilated in the emergency department, the majority had a blood gas checked while in the emergency department. While ABGs were associated with having changes made to ventilator settings in the emergency department, clinical findings of hypoxemia, hyperoxia, hypercapnia, and acidemia were not. Inattention to blood gas results may lead to missed opportunities in guiding ventilator changes in the emergency department.
... The base deficit score refers to a deficit of "base" present in the blood. Base deficit scores were first established by Davis et al. [35]. The base deficit score has been found correlated to many variables in the trauma population, such as, mechanism of injury, the presence of intra-abdominal injury, transfusion requirements, mortality, the risk of complications, and the number of days spent in the intensive care unit as indicated by Tremblay et al. [36] and Davis et al. [37]. ...
... A literature review identified over 20 studies interrogating the utility of vital signs in identifying shock from the three largest national trauma datasets: the National Trauma Database (NTDB) (USA), the Trauma and Audit research Network (TARN) (UK) and the Trauma DGU (Germany) (See appendix). There have also been numerous retrospective studies on this topic using databases from individual institutions [10][11][12][13][14][15][16][17]. Although the analytical methods used vary between these studies, consistent observations are that heart rate is a poor marker of blood loss and that hypotension, defined as a systolic blood pressure of <90 mmHg, is a late sign. ...
Introduction:
An assessment of physiological status is a key step in the early assessment of trauma patients with implications for triage, investigation and management. This has traditionally been done using vital signs. Previous work from large European trauma datasets has suggested that base deficit (BD) predicts clinically important outcomes better than vital signs (VS). A BD derived classification of haemorrhagic shock appeared superior to one based on VS derived from ATLS criteria in a population of predominantly blunt trauma patients. The initial aim of this study was to see if this observation would be reproduced in penetrating trauma patients. The power of each individual variable (BD, heart rate (HR), systolic blood pressure (SBP), shock index(SI) (HR/SBP) and Glasgow Coma Score (GCS)) to predict mortality was then also compared.
Methods:
A retrospective analysis of adult trauma patients presenting to the Pietermaritzburg Metropolitan Trauma Service was performed. Patients were classified into four "shock" groups using VS or BD and the outcomes compared. Receiver Operator Characteristic (ROC) curves were then generated to compare the predictive power for mortality of each individual variable.
Results:
1863 patients were identified. The overall mortality rate was 2.1%. When classified by BD, HR rose and SBP fell as the "shock class" increased but not to the degree suggested by the ATLS classification. The BD classification of haemorrhagic shock appeared to predict mortality better than that based on the ATLS criteria. Mortality increased from 0.2% (Class 1) to 19.7% (Class 4) based on the 4 level BD classification. Mortality increased from 0.3% (Class 1) to 12.6% (Class 4) when classified based by VS. Area under the receiver operator characteristic (AUROC) curve analysis of the individual variables demonstrated that BD predicted mortality significantly better than HR, GCS, SBP and SI. AUROC curve (95% Confidence Interval (CI)) for BD was 0.90 (0.85-0.95) compared to HR 0.67(0.56-0.77), GCS 0.70(0.62-0.79), SBP 0.75(0.65-0.85) and SI 0.77(0.68-0.86).
Conclusion:
BD appears superior to vital signs in the immediate physiological assessment of penetrating trauma patients. The use of BD to assess physiological status may help refine their early triage, investigation and management.
Background: Patients undergoing trauma laparotomy experience high rates of surgical site infection (SSI). Although intra-operative shock is a likely contributor to SSI risk, little is known about the relation between shock, intra-operative restoration of physiologic normalcy, and SSI development. Patients and Methods: A retrospective review of trauma patients who underwent emergent definitive laparotomy was performed. Using shock index and base excess at the beginning and end of laparotomy, patients were classified as normal, persistent shock, resuscitated, or new shock. Univariable and multivariable analyses were performed to identify predictors of organ/space SSI, superficial/deep SSI, and any SSI. Results: Of 1,191 included patients, 600 (50%) were categorized as no shock, 248 (21%) as resuscitated, 109 (9%) as new shock, and 236 (20%) as persistent shock, with incidence of any SSI as 51 (9%), 28 (11%), 26 (24%), and 32 (14%), respectively. These rates were similar in organ/space and superficial/deep SSIs. On multivariable analysis, resuscitated, new shock, and persistent shock were associated with increased odds of organ/space SSI (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.3-3.5; p < 0.001) and any SSI (OR, 2.0; 95% CI, 1.4-3.2; p < 0.001), but no increased risk of superficial/deep SSI (OR, 1.4; 95% CI, 0.8-2.6; p = 0.331). Conclusions: Although the trajectory of physiologic status influenced SSI, the presence of shock at any time during trauma laparotomy, regardless of restoration of physiologic normalcy, was associated with increased odds of SSI. Further investigation is warranted to determine the relation between peri-operative shock and SSI in trauma patients.
Cardiac and hemodynamic monitoring are the cornerstones of modern-day critical care. Previous groundwork has characterized cardiac physiology and the pathophysiology that occurs during shock and other disorders disrupting homeostasis. Fundamental to this understanding is the need to monitor cardiac and hemodynamic indices to provide point-of-care data that can be incorporated into the care of patients with physiologic compromise. This chapter will review the goals of resuscitation, recognition of shock in the elderly patient, and briefly review the cardiac and hemodynamic changes that occur with aging. Additionally, we will review standard and advanced hemodynamic techniques of monitoring and evaluate their strengths and limitations in the elderly ICU patient. Lastly, we will offer paradigms for hemodynamic and cardiac monitoring in the critically ill elderly patient with a focus on risk/benefit assessment and fluid responsiveness and finish with an individualized, patient centered approach to resuscitation and physiologic support during recovery from critical illness.KeywordsGoal-directed resuscitationHemodynamic monitoringEchocardiographyFluid responsivenessBioreactancePulse contour analysisNon-invasive monitoring
Clinical observations and physiological considerations support the view that oxygen debt is the major determinant of perioperative morbidity and mortality. Oxygen debt is defined as the negative balance between O2 demand and supply. When O2 delivery (DO2) reduces below the hypoxic threshold (DO2crit), O2 consumption (VO2) falls. The trespassing of the hypoxic threshold coincides with the switch from aerobic to anaerobic metabolism. This transition is marked by increased lactate production as a reflection of metabolic acid production. Failure of DO2 to satisfy metabolic requirements is the common denominator of all shock types. The relationship between VO2 and DO2 is characterized by the VO2/DO2 ratio, namely, the oxygen extraction ratio (O2ER). Normal O2ER values lie around 25%. O2ER can be regarded as a global index of the efficiency of O2 extraction. Above DO2crit, VO2 is supplied independently from delivery, so that it remains constant despite the changes of DO2. The oxygen extraction ratio moves in the opposite direction of DO2 to keep the VO2 constant. Therefore, as DO2 decreases, O2ER must increase. Conversely, O2ER increases as DO2 decreases. O2ER may be approximated by the SvO2/SaO2 ratio as the O2 content of blood is hemoglobin-bound for more than 98.5%. The main determinants of O2 delivery are Hb content, cardiac output, VO2, and PaO2. As the cardiac output is the most manipulating variable, it takes on the greatest importance in clinical diagnosis and therapy. Guyton’s analysis of circulation provides the rationale for the meaningful manipulation of circulatory variables as CVP and cardiac output in order to maintain circulatory homeostasis. Microcirculatory O2 diffusion is the physical process that ensures the provision of oxygen to the final user, the mitochondrion. The microcirculation is finely regulated by multiple physiologic mechanisms that ensure the adequacy of O2 supply during the different physical activities. Although finely tuned, microvascular perfusion is intrinsically heterogeneous. Increased heterogeneity because of augmented inter-capillary distance and decreased capillary flow represents the main determinant of microcirculatory shock. Microcirculatory dysfunction is thought to precede by several hours overt hypotension and decreased cardiac output. Once shock becomes manifested, the microcirculatory and macrocirculatory abnormalities coexist. Incomplete or delayed resuscitation is marked by the persistence of microcirculatory abnormalities, although normal or even supra-normal circulatory parameters have been achieved (e.g., arterial pressure and flow). Oxygen deficit is defined as the difference between baseline VO2, and VO2 measured at any given time during the shock period. O2 debt is, therefore, the accumulation of multiple oxygen deficits over time. Experimental studies suggest that the faster and the more complete is the O2 debt repayment, the lesser will be the resulting multiple organ dysfunction and failure. Conversely, a delayed or incomplete resuscitation entails the risk of irreversible organ damage by supra-maximal O2 debt accumulation. Efforts must be committed to prevent or at least limit O2 debt accumulation. Furthermore, the repayment of the debt must be aggressively pursued, minimizing the time of O2 debt resolution.
Consideration for blood products replacement in postpartum hemorrhage should be given when blood loss exceeds 1.5 L or when an estimated 25% of blood has been lost. In cases of massive hemorrhage, standardized transfusion protocols have been shown to improve maternal morbidity and mortality. Most protocols recommend a balanced transfusion involving a 1:1:1 ratio of packed red blood cells, platelets, and fresh frozen plasma. Alternatives such as cryoprecipitate, fibrinogen concentrate, and prothrombin complex concentrates can be used in select clinical situations. Although transfusion of blood products can be lifesaving, it does have associated risks.
Introduction:
Delayed diagnosis of abdominal injuries and hemorrhagic shock leads to secondary complications and high late mortality in severely traumatized patients. The liver fatty acid-binding protein (L-FABP) is expressed in intestine, liver and kidney; the neutrophil gelatinase-associated lipocalin (NGAL) in colon and kidney. We hypothesized that l-FABP is an early biomarker for abdominal injury and hemorrhagic shock and that l-FABP and NGAL are specific markers for detection of liver and/or kidney injuries.
Patients and methods:
Traumatized patients with an age ≥18 years and an abdominal injury (AISabd≥2), independently from Injury Severity Score (ISS), were prospectively included from 04/2018 to 05/2021. 68 patients had an abdominal injury ("Abd") and 10 patients had an abdominal injury with hemorrhagic shock ("HS Abd"). 41 patients without abdominal injury and hemorrhagic shock but with an ISS ≥ 25 ("noAbd") were included as control group. Four abdominal subgroups with isolated organ injuries were defined. Plasma l-FABP and NGAL levels were measured at admission (ER) and up to two days post-trauma.
Results:
All patient groups had a median ISS≥25. In ER, median l-FABP levels were significantly higher in "HS Abd" group (1209.2 ng/ml [IQR=575.2-1780.3]) compared to "noAbd" group (36.4 ng/ml [IQR=14.8-88.5]), and to "Abd" group (41.4 ng/ml [IQR=18.0-235.5]), p<0.001. In matched-pair-analysis l-FABP levels in the group "Abd" were significantly higher (108.3 ng/ml [IQR=31.4-540.9]) compared to "noAbd" (26.4 ng/ml [IQR=15.5-88.8]), p = 0.0016. l-FABP correlated significantly with clinical parameters of hemorrhagic shock; the optimal cut-off level of l-FABP for detection was 334.3 ng/ml (sensitivity: 90%, specificity: 78%). Median l-FABP-levels were significantly higher in patients with isolated liver or kidney injuries and correlated significantly with AST, ALT and creatinine value. Median NGAL levels in the ER were significantly higher in "HS Abd" group (115.9 ng/ml [IQR=90.6-163.8]) compared to "noAbd" group (58.5 ng/ml [IQR=41.0-89.6],p<0.001) and "Abd" group (70.5 ng/ml [IQR=53.3-115.5], p<0.05). The group "Abd" showed significant higher median NGAL levels compared to "noAbd", p = 0.019. NGAL levels correlated significantly with clinical parameters of hemorrhagic shock.
Conclusion:
L-FABP and NGAL are novel biomarkers for detection of abdominal trauma and hemorrhagic shock. l-FABP may be a useful and promising parameter in diagnosis of liver and kidney injuries, NGAL failed to achieve the same.
Trauma patients present a unique challenge to anesthesiologists, since they require resource-intensive care, often complicated by pre-existing medical conditions. This fully revised new edition focuses on a broad spectrum of traumatic injuries and the procedures anesthesiologists perform to care for trauma patients perioperatively, surgically, and post-operatively. Special emphasis is given to assessment and treatment of co-existing disease, including surgical management of trauma patients with head, spine, orthopedic, cardiac, and burn injuries. Topics such as training for trauma (including use of simulation) and hypothermia in trauma are also covered. Six brand new chapters address pre-hospital and ED trauma management, imaging in trauma, surgical issues in head trauma and in abdominal trauma, anesthesia for oral and maxillofacial trauma, and prevention of injuries. The text is enhanced with numerous tables and 300 illustrations showcasing techniques of airway management, shock resuscitation, echocardiography and use of ultrasound for the performance of regional anesthesia in trauma.
Background:
The outcome in patients of atlanto-axial dislocation (AAD) depends on multiple factors like preoperative optimization, intraoperative distractio and cord manipulation. Certain unfocussed factors such as respiratory reserve and compensatory acclimatization to hypoxia warrant consideration.
Aims:
The purpose of this study is to find the association of postoperative arterial blood gas (ABG) analysis and respiratory reserve in patients of AAD with clinical outcome.
Study design:
We retrospectively analyzed the available records of patients, operated for AAD, at our institute (n = 66), from January 2014 to November 2018.
Materials and methods:
Preoperative pulmonary function test (PFT) and the postoperative ABG analysis was noted. Timing of extubation, duration of intensive care unit (ICU) stays, and clinical outcomes (Nurick grade) were noted from the inpatient record and the last outpatient follow up. An independent t-test and analysis of variance were used to find significance.
Results:
In total, 41% (n = 27) patients had body mass index of less than 18.5, and 50% (n = 33) had breath holding time of less than 20 minutes. There was improvement in mean Nurick grade from 3.17 ± 0.8 to 2.76 ± 0.7 in follow up. A trend suggesting that patients with poor preoperative PFT has more ICU duration and worse outcome. In patients with mild acid-base disorders, extubation was possible within 24 hours. Out of 26 patients with ICU duration less than 2 days, 23 patients had "good" outcome, whereas ten out of 40 patients with ICU duration of more than or equal to 2 days had "bad" outcome (P = 0.00).
Conclusion:
Patients having moderate to severe primary or mixed acid-base disorder have a probability of re-intubation or delayed extubation. A strong correlation was seen with the novel grading system (grade >6 had worse outcome).
Thoracic trauma is frequently severe enough to require admission to the intensive care unit (ICU). As with all trauma patients, providers need to be adept at simultaneous assessment, resuscitation, and treatment. In addition, it is important to be proactive to prevent sequelae. The three pillars of multi-disciplinary ICU care for these patients are resuscitation, pulmonary support, and pain control.KeywordsTeam-based careCritically illRespiratory support
ISS5以上の鈍的外傷患者を対象とした。診療録から患者背景，24時間以内のRCC輸血量，搬入直後の血液検査結果などを後ろ向きに収集し，大量出血群と非大量出血群で比較した。搬入後24時間以内にRCC10単位以上の輸血を行った群を大量出血群と定義した。【結果】695名が参加基準を満たした。大量出血群は91名，非大量出血群は604名であった。ISS，GCS，収縮期血圧，年齢，血糖値，PT，APTT，フィブリノゲン，D–dimer，イオン化Ca，BDについて多変量ロジスティック回帰解析を行ったところ，ISS，血糖値，BDのみが独立した大量出血の予測因子として選択された。血糖値のROC曲線下面積は，0.811（95%CI 0.755–0.868）でありカットオフ値は177となった。血糖値177以上での大量出血に対するオッズ比は11.36（95%CI 6.88–18.76），200以上で18.24（95%CI 10.53–32.21），300以上で29.85（95%CI 9.65–92.29）となった。同様に，BDのROC曲線下面積は0.80（95%CI 0.74–0.85）となり，カットオフ値は－3.25となった。【結語】今回大量出血の予測因子としてISS，BD，血糖値が選択された。BD，血糖値は，どの施設でも簡便，迅速に検査できる項目であり，大量出血の予測因子として有用と考えられる。 Background: Recently, there are some studies evaluating whether hyperglycemia on admission is predictive of mortality and morbidity in trauma patients. However, no study has examined the association between hyperglycemia and massive transfusion (MT). We hypothesized that serum glucose level in admission could potentially predict the need for MT in trauma patients. Methods: Data was collected on all blunt trauma patients admitted to Senshu Critical Care Medical Center from May 2006 through September 2011. Inclusion criteria were injury severity score (ISS) > 4, and age > 15. Exclusion criteria were cardiopulmonary arrest on arrival, referral from other hospitals, and diabetes. MT was defined as transfusion of more than 10 units of RCC within 24 hours of admission. A multivariable logistic regression analysis was performed for ISS, Glasgow coma scale (GCS), systolic blood pressure, age, glucose, PT, APTT, platelet, fibrinogen, d–dimer, ionized Ca and base deficit (BD). Results: 695 patients met the inclusion criteria, in which 91 patients received MT. ISS, glucose and BD were identified as independent predictive factor for MT. Receiver operator characteristic (ROC) curves for glucose, ISS, and BD showed area under the curve of 0.811 (95% confidence interval [CI] 0.755–0.868), 0.860 (95% CI 0.825–0.895), 0.800 (95% CI 0.748–0.852), respectively. Conclusions: Coagulopathy has been shown to be associated with the incidence of MT after trauma, however, in our study, only ISS, hyperglycemia, and acidosis on admission were identified as independent predictors of MT. Admission hyperglycemia in conjunction with BD may rapidly identify patients requiring massive transfusion, allowing for earlier institution of appropriate resuscitation protocols.
Background:
The base excess (BE) parameter can be used as an indicator of mortality. However, study results on the influence of alcohol on the validity of BE as a prognostic parameter in alcohol-intoxicated patients are controversial. Thus, this study examined the hypothesis: An increasing blood alcohol level reduces the prognostic value of the Base Excess parameter on mortality.
Material methods:
In a retrospective analysis of the multi-centre database of the TraumaRegister DGU®, patients from 2015 to 2017 were grouped depending on their blood alcohol level (BAL) into a BAL+ and BAL- group. The hypothesis was verified using logistic regression with an assumed significance level of 1% (p < 0.01).
Results:
11889 patients were included; 9472 patients in the BAL- group and 2417 patients in the BAL+ group. Analysis of the BE showed lower values in the BAL+ group (BAL-: -1.8 ± 4.4 mmol/l vs. BAL+: -3.4 ± 4.6 mmol/l). There is a trend towards lower BE levels when BAL increases. Assuming a linear relationship, then BE decreases by 0.6 points per mille alcohol (95%CI: 0.5-0.7; p < 0.001). The mortality rate was significantly lower in the BAL+ group (BAL-: 11.1% vs. BAL+: 7.9%). The logistic regression analysis showed a significant beneficial influence of BAL+ on the mortality rate (OR 0.706, 95% CI 0.530 - 0.941, p = 0.018). To analyse whether a low BE (≤ -6 mmol/l) has different prognostic effects in patients with and without alcohol, logistic regression models were calculated. However, the effect of BE ≤ -6 mmol/l was similar in both models (regression coefficients in BAL-/+ patients: 0.379 / 0.393).
Conclusions:
The data demonstrate an existing influence of alcohol on the BE parameter; however, this does not negatively affect the BE as a prognostic parameter at a threshold of ≤ -6 mmol/l.
Every year across the United States, between 500,000 and 1 million patients are treated in intensive care units for injuries resulting from traumatic mechanisms. The therapies provided in these intensive care units are paramount to the recovery and well-being of these patients. And while no single factor is solely responsible or optimal care of trauma patients, several key variables have been identified as critical elements of appropriate trauma intensive care. Broadly speaking, the hallmarks of an optimal trauma intensive care unit include infrastructure designed with the consideration of trauma needs, personnel dedicated to the care of trauma patients, as well as an encompassing armamentarium of resuscitation tools. These should include, but are not limited to, invasive and noninvasive hemodynamic monitors, point of care biochemical testing, and algorhythmic based practice management guidelines focused on minimizing system- and user- based errors. Similar to other fields of critical care practice, the optimal care of trauma patients managed in an intensive care unit must be informed, and guided by, rigorous evidence-based guidelines and expert level opinions.
Exsanguinating trauma is a major cause of death from trauma. Fluid resuscitation strategies have evolved remarkably since the 1980’s. Crystalloids, particularly lactated Ringer’s solution, were the initial fluids of choice before administering blood products. Subsequent studies have demonstrated that balanced crystalloids are likely better than normal saline and that hypertonic saline or colloids have little benefit. For patients with severe hemorrhagic shock, however, early administration of blood products, including packed red blood cells, plasma, and platelets, as part of a damage control resuscitation strategy, improves outcomes. Large amounts of crystalloids should be avoided. Monitoring thromboelastography may help. In select patients, this strategy may include administration of tranexamic acid or prothrombin complex concentrates. For patients with evidence of ongoing hemorrhage, hypotensive or limited fluid resuscitation is appropriate until hemostasis has been achieved. Details of optimal fluids or blood pressure goals still need to be determined. Once hemostasis has been achieved, fluid resuscitation should continue in order to achieve appropriate endpoints, which may include normalization of vital signs and urine output, decreasing lactate level or base deficit, or a minimization of additional fluid responsiveness based upon echocardiography or pulse waveform analysis.
Background
Base Deficit (BD) and lactate have been used as indicators of shock and resuscitation. This study was done to evaluate the utility of BD and lactate in identifying shock and resuscitative needs in trauma patients.
Methods
A prospective observational study was performed from 3/2014-12/2018. Data included demographics, admission systolic BP, ISS, BD, lactate, blood transfusion, and outcomes. BD and lactate were modeled continuously and categorically and compared.
Results
2271 patients were included. BD and lactate were moderately correlated (r² = 0.63 p < 0.001). On univariate regression, BD and lactate were associated with transfusion requirement and mortality (p < 0.001), but on multivariate regression, only BD was associated with transfusion requirement and mortality (OR = 1.2, p < 0.001; OR = 1.1, p < 0.001, respectively). BD discriminated better than lactate for hypotension, higher ISS, increased transfusion requirements and mortality.
Conclusions
Admission BD and lactate levels are correlated following injury, but BD is superior to lactate in identifying shock, resuscitative needs and mortality in severely injured trauma patients.
Background:
To compare admission lactate and base deficit (BD), which physiologically reflect early hemorrhagic shock, as outcome predictors of pediatric trauma.
Methods:
We reviewed the data of children with trauma who visited a Korean academic hospital from 2010 through 2018. Admission lactate and BD were compared between children with and without primary outcomes. The outcomes included in-hospital mortality, early (≤24 hours) transfusion, and early surgical interventions for the torso or major vessels. Subsequently, performances of lactate and BD in predicting the outcomes were compared using receiver operating characteristic curves. Logistic regressions were conducted to identify the independent associations of the two markers with each outcome.
Results:
Of the 545 enrolled children, the mortality, transfusion, and surgical interventions occurred in 7.0%, 43.5%, and 14.9%, respectively. Cutoffs of lactate and BD for each outcome were as follows: mortality, 5.1 and 6.7 mmol/L; transfusion, 3.2 and 4.9 mmol/L; and surgical interventions, 2.9 and 5.2 mmol/L, respectively. No significant differences were found in the areas under the curve for each outcome. Of the two markers, a lactate of >5.1 mmol/L was associated with mortality (adjusted odds ratio, 6.43; 95% confidence interval, 2.61-15.84). A lactate of >3.2 mmol/L (2.82; 1.65-4.83) and a BD of >4.9 mmol/L (2.32; 1.32-4.10) were associated with transfusion, while only a BD of >5.2 mmol/L (2.17; 1.26-3.75) was done with surgical interventions.
Conclusions:
In pediatric trauma, lactate is more strongly associated with mortality. In contrast, BD may have a marginally stronger association with the need for hemorrhage-related procedures.
Blood product transfusion capabilities are crucial for appropriate response to postpartum hemorrhage. Novel treatments are continually being sought to improve maternal morbidity and mortality associated with massive hemorrhage.
The role of the anesthesiologist in damage control trauma care is that of resuscitation consultant. Damage control anesthesia must occur in concert with damage control resuscitation and surgery to optimize the physiology of the shocked patient, while ensuring adequate surgical conditions for the operative team. Damage control anesthesia encompasses a variety of procedural skills, from the induction of anesthesia to advanced airway management techniques and to the full spectrum of vascular access options. Beyond providing only procedural assistance in the resuscitation, the anesthesiologist offers the unique perspective of a physician who spends each day monitoring and correcting deranged physiology in the operating room.
Damage control resuscitation has been increasingly adopted and practiced over the last decade. The concepts used are not new to this era of medicine but are novel in combination. This chapter will focus on adjuncts to damage control resuscitation (DCR) including massive transfusion protocols, the “other” tenets of damage control resuscitation, hypertonic saline, tranexamic acid, pharmacologic resuscitation, Factor VIIa, and prothrombin complex, and viscoelastic testing.
Emergency physicians face the challenge of rapidly identifying high-risk trauma patients. Lactate (LAC) is widely used as a surrogate of tissue hypoperfusion. However, clinically important values for LAC as a predictor of mortality are not well defined. Objectives: 1. To assess the value of triage LAC in predicting mortality after trauma. 2. To compute interval likelihood ratios (LR) for LAC.
Methods
Retrospective chart review of trauma patients with a significant injury mechanism that warranted labs at an urban trauma center. Outcome: In-hospital mortality. Data are presented as median and quartiles or percentages with 95% confidence intervals. Groups (lived vs. died) were compared with Man-Whitney-U or Fisher's-exact test. Multivariate analysis was used to measure the association of the independent variables and mortality. The interval likelihood ratios were calculated for all LAC observed values.
Results
10,575 patients; median age: 38 [25–57]; 69% male; 76% blunt; 1.1% [n = 119] mortality. LAC was statistically different between groups in univariate (2.3 [1.6,3.0] vs 2.8 [1.6,4.8], p = 0.008) and multivariate analyses (odds ratio: 1.14 [1.08–1.21], p = 0.0001). Interval ratios for LR- ranged from 0.6–1.0. Increasing LAC increased LR +. However, LR + for LAC reached 5 with LAC > 9 mmol/L and passed 10 (moderate and conclusive increase in disease probability, respectively) with LAC > 18 mmol/L.
Conclusions
In a cohort of trauma patients with a wide spectrum of characteristics triage LAC was statistically able to identify patients at high risk of mortality. However, clinically meaningful contribution to decision-making occurred only at LAC > 9. LAC was not useful at excluding those with a low risk of mortality.
Background:
Mechanical ventilation after general surgery is associated with worse outcomes, prolonged hospital stay, and increased health care cost. Postoperatively, patients admitted to the intensive care unit (ICU) may be categorized into 1 of 3 groups: extubated patients (EXT), patients with objective medical indications to remain ventilated (MED), and patients not meeting these criteria, called "discretional postoperative mechanical ventilation" (DPMV). The objectives of this study were to determine the incidence of DPMV in general surgery patients and identify the associated operative factors.
Methods:
At a large, tertiary medical center, we reviewed all surgical cases performed under general anesthesia from April 1, 2008 to February 28, 2015 and admitted to the ICU postoperatively. Patients were categorized into 1 of 3 cohorts: EXT, MED, or DPMV. Operative factors related to the American Society of Anesthesiologists Physical Status (ASA PS), duration of surgery, surgery end time, difficult airway management, intraoperative blood and fluid administration, vasopressor infusions, intraoperative arterial blood gasses, and ventilation data were collected. Additionally, anesthesia records were reviewed for notes indicating a reason or rationale for postoperative ventilation. Categorical variables were compared by χ test, and continuous variables by analysis of variance or Kruskal-Wallis H test. Categorical variables are presented as n (%), and continuous variables as mean ± standard deviation or median (interquartile range) as appropriate. Significance level was set at P≤ .05.
Results:
Sixteen percent of the 3555 patients were categorized as DPMV and 12.2% as MED. Compared to EXT patients, those classified as DPMV had received significantly less fluid (2757 ± 2728 mL vs 3868 ± 1885 mL; P < .001), lost less blood during surgery (150 [20-625] mL vs 300 [150-600] mL; P< .001), underwent a shorter surgery (199 ± 215 minutes vs 276 ± 143 minutes; P< .001), but received more blood products, 900 (600-1800) mL vs 600 (300-900) mL. The DPMV group had more patients with high ASA PS (ASA III-V) than the EXT group: 508 (90.4%) vs 1934 (75.6%); P< .001. Emergency surgery (ASA E modifier) was more common in the DPMV group than the EXT group: 145 (25.8%) vs 306 (12%), P< .001, respectively. Surgery end after regular working hours was not significantly higher with DPMV status compared to EXT. DPMV cohort had fewer cases with difficult airway when compared to EXT or MED. When compared to MED patients, those classified as DPMV received less fluid (2757 ± 2728 mL vs 4499 ± 2830 mL; P< .001), lost less blood (150 [20-625] mL vs 500 [200-1350] mL; P < .001), but did not differ in blood products transfused or duration of surgery.
Conclusions:
In our tertiary medical center, patients often admitted to the ICU on mechanical ventilation without an objective medical indication. When compared to patients admitted to the ICU extubated, those mechanically ventilated but without an objective indication had a higher ASA PS class and were more likely to have an ASA E modifier. A surgery end time after regular working hours or difficult airway management was not associated with higher incidence of DPMV.
A total of 410 critically ill patients in critical care units of six community hospitals were surveyed for a period of 31 days. A prognostic index of survival was derived by discriminant function analysis utilizing measurement of blood lactate, blood pressure, heart rate, arrhythmias, spontaneous respiration, urine volume, body temperature, age, and a five-point rating of clinical condition by the nursing staff. The case fatality rate in patients in whom blood lactate exceeded 2.7 mM was 50% fatality rate was 5% when lactate was less than 2.7 mM. The best prediction of survival was obtained by combining the plasma lactate and the five-point rating of the patient's condition. These data therefore could serve as a measure of the severity of illness at the time of admission and provide a quantitative guide for objective comparison of the effectiveness with which critical care services are delivered in acute care units. They can also provide an objective basis for priority assignment to cardiac care, intensive care, and other specialized units of the hospital
A method for comparing death rates of groups of injured persons was developed, using hospital and medical examiner data for more than 2,000 persons. The first step was determination of the extent to which injury severity as rated by the Abbreviated Injury Scale correlates with patient survival. Substantial correlation was demonstrated. Controlling for severity of the primary injury made it possible to measure the effect on mortality of additional injuries. Injuries that in themselves would not normally be life threatening were shown to have a marked effect on mortality when they occurred in combination with other injuries. An Injury Severity Score was developed that correlates well with survival and provides a numerical description of the overall severity of injury for patients with multiple trauma. Results of this investigation indicate that the Injury Severity Score represents an important step in solving the problem of summarizing injury severity, especially in patients with multiple trauma. The score is easily derived, and is based on a widely used injury classification system, the Abbreviated Injury Scale. Use of the Injury Severity Score facilitates comparison of the mortality experience of varied groups of trauma patients, thereby improving ability to evaluate care of the injured.
The blood lactic acid concentration is a reflection of the quantity of lactic acid produced by a number of tissues and the quantity metabolized primarily by the liver. Tissue hypoxia due to circulatory, respiratory, hematologic or cellular dysfunction leads to lactic acid overproduction whereas hepatic underfusion results in underutilization. Most instances of lactic acidosis occur as a result of both overproduction and underutilization. The most common cause of lactic acidosis is shock. Lactic acidosis occurs early in shock and may precede a fall in blood pressure, decrease in urine output and other signs of reduced peripheral perfusion. Lactate levels above 7 to 8 mEq per L are usually associated with a fatal outcome. Other conditions associated with lactic acidosis include diabetes, phenformin therapy, leukemia, glycogen storage disease, ethanol ingestion and spontaneous lactic acidosis. Elevated blood lactate levels may occur in association with metabolic alkalosis due to bicarbonate therapy and with respiratory alkalosis due to hyperventilation. Prolonged hyperventilation has not been shown to progress to lactic acidosis clinically.Severe lactic acidosis of any cause leads to circulatory insufficiency which begets lactic acidosis. Adequate peripheral perfusion and prompt restoration of pH towards normal are essential for immediate survival. Ultimate survival depends on the ability to identify and remove the cause of the lactic acid overproduction.
1.1. Serial determinations of lactate, excess lactate, pH, and base excess were obtained in a group of sixty-nine patients with hemorrhagic, septic, cardiogenic, or neurogenic shock and fifteen injured patients not in shock. All patients received Ringer's lactate solution and most received whole blood during the period of resuscitation.2.2. There was a significant decrease in lactate and excess lactate levels and a return toward normal of pH and base excess values during the period of shock while Ringer's lactate solution was being infused. After resuscitation, all these values rapidly returned to normal levels.3.3. Lactate and excess lactate levels correlate well with the clinical impression of the depth of shock, but the injuries producing the shock state have a much greater bearing on ultimate prognosis.4.4. The degree of correlation between lactate and excess lactate is low when the lactate level is below 10 mM/L.
Many trauma victims who have hemorrhagic shock are also intoxicated. Ethanol could worsen the severity of shock and decrease the amount of blood loss necessary to reach or maintain the shock state, perhaps by increasing lactic acidosis. We examined the effect of ethanol on lactic acidosis in a group of rats that were intoxicated, then put in a state of hemorrhagic shock (MAP = 40 mm Hg). These animals were compared to a control group that were in a similar state of hemorrhagic shock but not intoxicated. The volumes of blood necessary to reach and maintain the predetermined model state of shock for two hours in each group were also measured. The animals were paralyzed and placed on controlled ventilation. The ethanol produced an expected baseline lactic acidosis, and it took significantly less blood volume loss to keep the intoxicated group in shock. However, during shock there was no significant difference in the state of lactic acidosis. These results suggest that acute ethanol intoxication made the animals more sensitive to hemorrhage. This effect was not mediated by an increase in lactic acidosis in our model.
Thirteen baboons were bled into shock and maintained at 60 mm Hg and 40 mm Hg for 2 hours, respectively, followed by resuscitation with shed blood and Ringer's lactate. In eight animals restoration of baseline left atrial pressure (LAP) was considered complete resuscitation and was maintained at baseline values with infusion of Ringer's for 18 hours. Five animals were resuscitated to baseline mean arterial pressure (MAP) and maintained with Ringer's. Complete hemodynamic parameters were recorded preshock, during shock, and hourly post-resuscitation for 18 hours. Organ blood flow was measured from radioactive microsphere injections at baseline, during shock, and 2 and 18 hours post-resuscitation. Blood volume was determined (Evans' blue) at baseline and 18 hours. Characteristic hemodynamic changes were noted with shock which returned to normal for the 18 hours post-resuscitation. Animals resuscitated to baseline MAP remained stable with additional small volumes of Ringer's whereas, using LAP as the parameter for resuscitation, increasing fluid requirements to maintain LAP, began at 3 to 4 hours and was paralleled by a corresponding increase in urine output. At 18 hours intake was 450 cc/hour and output nearly 350 cc/hour (both [asymptotically equal to] 4 times baseline). Organ blood flow altered as expected during shock and at 18 hours persistent, significant (p < 0.05) reduction in organ blood flow was noted in the splanchnic circulation (gut and spleen) in both groups. Blood volume was significantly below baseline (< 90%) at 18 hours. The data suggest a persistence of a teleologically important mechanism to protect the organism during shock which is not shut off by effective resuscitation as judged by hemodynamic criteria. Furthermore, the excessive fluid intake and output necessary to maintain baseline LAP suggest resetting of normal mechanisms for regulation of blood volume, and LAP may then not be a reliable parameter of resuscitation from hemorrhagic shock. These observations describe a prolonged abnormality in blood volume and flow distribution which may contribute to the syndrome of multiple organ failure following resuscitation from shock.
On the basis of previous studies, it has been sug-gested that lactic acid production by tissues may be regarded as a function of the effectiveness of oxygen supply to them (1-3). However, these studies are subject to certain technical objections (4), and various other investigations have ap-peared to show either a different relationship (5, 6) or no relationship of lactate to 02-debt (2, 7, 8) or hypoxia (9). Furthermore, a variety of conditions unrelated to oxygen deficiency have been found to cause lactate production in the in-tact body (4). Therefore, it seems unwarranted at present to ascribe alterations in body lactate, or in lactate exchanges of organs, to oxygen de-ficiency of the tissues. The essential element of the original suggestion by Hill, Long, and Lupton that lactate production is associated with oxygen deficiency in the intact body was an apparent relationship between lac-tate and 02-debt found under very special circum-stances (1, 10, 11). We have been unable to con-firm this relationship strictly, as will be seen in the present data. The development of knowledge about the lactic dehydrogenase system in recent years, moreover, makes such a relationship appear to have been a special circumstance rather than a general principle, since changes in pyruvate affect lactate levels as much as does oxygen lack (4), and the fundamentally parallel effect of pyruvate and hypoxia on lactate production is shown by the equation of the lactic dehydrogenase equilibrium. If a lactate change, however, exceeds that which is appropriate, according to this relationship, to the alterations in pyruvate, then there would ap-pear to be only one explanation for the excess, i.e., oxygen deficiency. Calculations of this "ex-cess lactate" (XL) previously made (4) show this quantity to be essentially zero during marked ' Aided in part by a grant from the American Heart Association. lactate production from nonhypoxic causes. The present data on exercise indicate the magnitude of ''excess lactate" production during tissue hypoxia and the quantitative relationships between total lactate, XL and respiratory 02-debt. METHODS Human subjects without cardiac or respiratory disease came to the laboratory fasting and rested for an hour or more in bed after an indwelling needle was placed in one brachial artery with local anesthesia. Exercise was car-ried out by two methods for the purpose of producing 02-debts of various magnitudes. The severe exercise consisted of walking on a motor-driven treadmill; the mild exercise consisted of straight leg raising in the su-pine position. No further attempt was made to regulate the work done. Exercise lasted from 7 to 15 minutes. Blood was collected from the brachial artery as previ-ously described (12) at frequent intervals during rest, exercise and recovery. Recovery was followed for one and one-half to two hours. Samples were analyzed for lactate, pyruvate and oxygen as previously described (4). Blood oxygen saturations exceeded 96 per cent in every instance. Expired air was collected continuously during the se-vere exertion and intermittently during the mild exer-cise; collection was continuous from the last minute of exercise throughout the recovery period in all experi-ments. Timed air collections were carried out through a rubber mouthpiece, low resistance valve and short length of tubing leading to two Douglas bags used al-ternately. The volume of gas in each bag was deter-mined either by drawing the contents through a care-fully calibrated wet-test gas meter at constant pressure and rate of flow, or by determining the dilution volume of a measured quantity of acetylene in the bag. The ex-pired air was analyzed for oxygen and carbon dioxide either in the Haldane apparatus or in the paramagnetic oxygen analyzer (Beckman, Model E2 null-point ana-lyzer with total range 12 to 22 per cent) before and after passage through soda-lime and sodium hydroxide. The analyzer was used at constant pressure and rate of flow. Collection periods were two to five minutes in length. From the volume and composition of inspired and ex-pired air, rate of oxygen consumption was obtained for each period. Total body water was determined in each subject as the dilution volume of 4-aminoantipyrine (13).